Abstract: A method and arrangement in connection with the ventilation of a patient, wherein the lungs of the patient are ventilated mechanically by means of a ventilator or manually by means of a reservoir bag as the patient's own respiratory activity is insufficient or totally prevented. In order to eliminate a faulty connection, the behaviour of the pressure or the flow in the patient circuit, in the circuit associated with the ventilator or in the circuit associated with the reservoir bag is monitored in connection with ventilation and the obtained information is compared with the desired operation.

Abstract: An arrangement in connection with a ventilator that comprises a control unit, a bellows unit and a patient circuit, whereby the bellows unit is arranged to separate the control unit from the patient circuit and the control unit is arranged to implement control parameters characterizing lung ventilation. In order to eliminate human error, the arrangement is provided with an identification device that is arranged to identify the bellows unit to be used and to give notification on said bellows unit.

Abstract: An apparatus for the regulation of a gas volume delivered to a patient during a respiratory cycle. The apparatus includes at least one valve (9 or 8) for discharging some of the propellant gas flowing from a propellant gas source (4) into a propellant gas chamber (18), the propellant gas chamber (18) being at least partially defined by a wall (17), having a second chamber (19) on the other side thereof. The location of said wall changes as the propellant gas pressure increases in the propellant gas chamber, thus increasing the volume of the propellant gas chamber, the volume of second chamber (19) on the other side of wall (17) diminishing, thus forcing the gas being delivered to a patient to flow towards a patient (21).